<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <style>
    * {
      padding: 0;
      margin: 0;
    }
    #wrapper {
      position: relative;
      left: 300px;
      top: 200px;
      width: 400px;
      height: 300px;
      overflow: hidden;
    }
    #wrapper ul {
      list-style: none;
      width: 2000px;
      height: 300px;
    }
    #wrapper ul li {
      float: left;
      width: 400px;
      height: 300px;
    }
    #wrapper ul li img {
      width: 100%;
      height: 100%;
    }
    .btnBox .btn {
      position: absolute;
      top: 50%;
      margin-top: -15px;
      width: 30px;
      height: 30px;
      line-height: 30px;
      text-align: center;
      background-color: black;
      opacity: 0.2;
    }
    .btnBox:hover .btn {
      opacity: 0.8;
    }
    .btnBox .left {
      left: 0;
    }
    .btnBox .right {
      right: 0;
    }
  </style>
  <body>
    <div id="wrapper">
      <ul>
        <li>
          <img src="./picture/picture0.jpg" alt="" srcset="" />
        </li>
        <li>
          <img src="./picture/picture1.jpg" alt="" srcset="" />
        </li>
        <li>
          <img src="./picture/picture2.jpg" alt="" srcset="" />
        </li>
        <li>
          <img src="./picture/picture3.jpg" alt="" srcset="" />
        </li>
        <li>
          <img src="./picture/picture0.jpg" alt="" srcset="" />
        </li>
      </ul>
      <div class="btnBox">
        <div class="btn left">&lt;</div>
        <div class="btn right">&gt;</div>
      </div>
      <div class="dot"></div>
    </div>
  </body>
</html>
